The NIH-EPA Chemical Information System, comprising 13 different components, such as the mass spectral search system, is under systematic development in a project that involves the collaborative efforts of 10 agencies in the U.S. and Europe. This multifaceted computer system is delivered to members of the international scientific community a fee-for-service basis via commercial networked computer systems and is currently being used by about 200 research scientists. Components of the Chemical Information System include programs and data bases in the areas of mass spectrometry, nmr spectrometry, structure determination by X-ray diffraction, X-ray crystal data, X-ray powder diffraction data, mass spectral bibliographic data, gas phase proton affinities, X-ray diffraction bibliographic data, and programs for NMR spectrum analysis, statistical analysis, and conformational analysis.